Pacific Oyster Mortality Syndrome (POMS) is a disease which affects Pacific Oysters (Crassostrea gigas) and is caused by a virus called OsHV-1 micro variant. It causes rapid death and high mortality rates in farmed Pacific Oysters (up to 100% within days of being detected) and can spread quickly if introduced.
POMS outbreaks within Australia
The first Australian case of POMS was recorded in 2010 in New South Wales, with the most recent outbreak in commercially-grown oysters detected in Tasmania in 2016.
South Australian POMS outbreak
In late February 2018, the first detection of POMS in South Australia was discovered in feral oysters in the Port River. The virus is now endemic in the Port River, with ongoing detection throughout 2018 and 2019. The most recent detection was in January 2020.
All commercial oyster growing areas in South Australia remain free of disease and efforts are focused on future proofing industry (e.g. biosecure hatcheries, POMS resistant oyster breeding program) and containing POMS to the Port River area.
POMS does not affect human health
There are no human health concerns associated with POMS, nor are there any food safety issues.
South Australia produces some of the finest Pacific oysters on the market and table oysters purchased from retailers, restaurants and fish processors are safe to eat.
How you can help protect SA's oyster industry
The general public can play a vital role in protecting South Australia’s oyster industry and the regional businesses and employment that depend on it.
If you are travelling into or through South Australia, you can help our oyster farming areas to remain disease free by following these steps:
- Adhere to the ban on removing bivalve shellfish from the Port River system from West Lakes to Port Gawler, including Section Bank. Bivalve shellfish such as oysters, mussels, cockles and razorfish should not be taken from the Port River area for any purpose, including bait or berley. See closure information
- Regardless of the point of purchase, check the origin of any oysters you are carrying.
- Dispose of any Tasmanian-sourced live oysters into landfill or at quarantine stations across SA.
- Never discard or store live oysters in any SA waters. It is an offence under the Fisheries Management Act 2007 to release or deposit exotic and/or aquaculture farmed species (such as Pacific Oysters) into the waters of South Australia and fines may apply.
- Do not use Pacific oysters, even when dead, as bait or berley.
- Never use seafood sold for human consumption (including imported seafood) as bait or berley.
- Boat owners should refer to the guidelines for good vessel cleaning practices.
PIRSA’s Biosecurity SA officers at quarantine stations at Yamba, Oodla Wirra, Pinnaroo and Ceduna also check for oysters while inspecting vehicles for fruit, vegetables, plants and plant related products as part of our regular efforts against fruit fly and other pests and diseases.
More information is available in the Ban on bringing live oysters from Tasmania into SA fact sheet. ()
Advice for oyster farmers: restrictions on importing oysters into SA
Since POMS was first detected in Australia (2010), general restrictions on importing oysters into SA have been in place to prevent disease introduction and safeguard South Australia’s oyster growing industry. These restrictions apply to several aquaculture species.
A total ban on the movement of live Pacific Oysters (including spat) originating from Tasmania into South Australia is also in place. Please ensure you regularly check this website for any updates. View the current livestock movement restrictions notice in relation to Pacific Oysters (page 574).
More information is available on the moving aquatic organisms page.
Detecting and reporting the disease
Oyster farmers are required to report unexplained oyster mortality of greater than 10% at grading, and particularly during warmer months with water temperatures above 17 degrees, to PIRSA.
Take the following steps to report the disease:
- Collect at least 40 live oysters from the mortality site.
- Collect another 40 samples from another batch where there are no unusual mortalities occurring, if possible.
- Calculate the percentage of oysters that have died.
- Bag, label, and place fresh samples on ice. Do not freeze.
- Courier samples to lab within 24 hours of collecting them.
- Report to Primary Industries and Regions SA (PIRSA) using the contact details below.
- Report to your Bay Representative or the South Australian Oyster Growers Association.
- Decontaminate personnel and equipment. See POMS decontamination advice ().
Further information is available in the Reporting POMS facts sheet ().
How to report POMS
POMS is a notifiable disease and must be reported immediately.
Report suspicion of POMS to Fishwatch: 1800 065 522